Drop hammer



March 26, 193-5. B. H, URSCHEL gp/M DROP HAMMER f 1 57 U 'Ol o l Eq a J affix/w11 March 26, 1935. B. H. URscHEL DROP HAMMER Filed May 21, 1952' 3 Sheets-Sheet 2 March 26, 1935. B H. URSCHEL 1,995,441

DROP HAMMER Filed May 2l, 1932 3 Sheets-'Sheet 3 dummy,

Patented Mar. 26, 1935 y UNITED STATES imam Y vlegami y intor- HAMMER Bertis H. Urschcl, ABcwling Green, Ohic y egalitarian May ai, 1932, serial Ne. 61am 7 Claims. v (or fzs-25) Y My invention has for itsl object to provide an efficient motor driven dropk forge hammer, pile driver or other machine, wherein a reciprocating member performs its .function by its accumulated momentum. The invention particularly relates to means for reducing the variations of the load on the motor used in driving drop'forged harnmers and the like and produces more uniform operation of the motor and less wear on the mechanism that interconnects the motor and the hammer head or plunger.

The invention provides a means for Ycontrolling the momentum of the hammer or-iplunger or other moving body, and causing reciprocatory movements of the body, the motor supplying the power consumed by the impacts occurring by theblows of the hammer. The invention thus produces a mechanism that consumes the energy of the driving motor at quite a uniform rate, means being provided for converting the energy of the motor as potential energy that is released or converted into vkinetic energy at times in the' reciprocatory movement of the hammer to produce a quite uniform load on the motor.

The invention also provides an automatic succeeding blows of the hammer to enable correct formation particularly of plastic orv semiplastic material, such as heatedmetal and the like. By the use of my invention the reciprocatory movements of the hammer head, per unit of time and with a given force, is greatly increased from that of drop forge hammers heretofore used, although the same motor power is used in operating the hammer. Y

The invention consists-in other features which will appear from the following description* and upon examination ofthe drawings; Structures containing the invention may partake of different forms and may be varied in their details and still embody the invention. To illustrate apractical application of the invention, have selected a drop forge hammer machine to which has beenapplied my invention and the modification thereof, the structures constituting two examples of the various machines and the details of such machines that contain the invention. Theyare described heremafter, it being understood that variations may be madev and that-certain features rof my invention may be used to advantage withouta corresponding use of other features of the inventionY and without departing from the spirit of the invention. The particular .structures selected are shown in the accompanying drawings. Y v f Fig. 1 of the kdrawings illustrates a front view of the. drop forge hammer machine selected as anexample. Fig. 2 illustrates a side View of parts of the machine. Fig, y3 illustrates .a wedge member for controlling a part of the machine. Fig. 4 illustrates a view` of a section of the machine taken on the line 4 4 indicated in Fig. 1. Fig. 5. illustrates a'vertical section of the hammer machine takenon the plane `at right angles to the plane on which'the section shown in Fig. 4 is taken. L Fig. 6 illustrates-.a View of a section of a roller bearing `member located in the upper end of .the :frame .of the machinaV Fig. 7 illustrates a'modification of a' structure'containing my invention. Fig'..8 is a view of a section of the hammer-head controlling parts shown in Fig. 7. i

wheels 3 to which may be Vconnected an electric motor, or other suitable source of power. 'Ihe hammer head 5 is suitably connected to a board 6 and in position to drop-to the anvil 7. The head and theanvil may be provided with suitable dies, if desired. The board 6 is located between the rollersA 2 and gripped thereby to 'raise the hammer head'5. As is usual indrop forge'hammer. constructions, the rollers 2 are mounted on shafts or bearing members 8 that are eccentrically supported in rotatable bearing members 9 that may be rotated by means/of arms 10 to move the rollersj 2 towards or away from each other to cause therollers 2 to clamp the board and lift the hammer'as the rollers are driven bythesource of power operating through the pulley wheels 3. A suitable 'means is provided for interconnecting the arms 10 and the hammer head 5 and for shifting the rollers to release'the board and allow the hammer tofdro-p, inthe manner well known in the-art. In the particular lform of drop forge lil Til,

hammer shown in the drawings, the movement of the hammer head 5 is controlled by a suitable rod V12 that is moved by the hammer head when the hammer head is raised to a certain point, the rod operating through the arms 10 to release the rollers and allow the hammer to drop. The rod 12 is provided with a suitable friction means for securing it in the position to which it is moved and adjustable arms 14 and 161, that are engaged by a pin 15, are connected to the hammer that operate'sto raise the arms 10 and release the board. The arm 16 may be engaged by the pin 15 to move the rollers 2 towards each other and clamp the board and thus raise the A hammer 5. Also, the movement of the hammer 5 may be controlled by the pressure of a suitable pedal 18 which operates a lever 19 that is connected by means of .a rod 20 to the arms 10 to produce the same relative movement of the rollers 2 to manipulate the hammer, in the manner well known in the art.

Y In the application of my invention to the forge hammer of the type illustrated, the reciprocatory part of the machine, such as the hammer head 5, is connected to two pairs of pistons 25 and 26 located in cylinders 27 and 28 having adjusted telescopic heads 29 and 30, and having lengths suicient to permit the desired maximum stroke of the hammer head 5. The pistons 25 and 26 are located on the ends of suitable rods 31 that may be connected to arms 32 that project laterally from the hammer head. The cylinders 27 and 28 are located in the standards or uprights that form parts'of the frame 1, of the machine, and are suitably secured in position by brackets 34; The adjustable telescoping heads 29 and 30 are secured in position by means of the brackets 35.Y `The brackets 35 may be provided with slots 36 in whichbolts 37 may be located whereby adjustment of the heads 29 and 30 may be made to vary theY volume of the end portion o'f the' cylinder and vary the degree of pressure existing at the completion ofthe maximum inward strokes of the pistons; This enables adjustment of the pressure per unit of area produced by the pistons upon the completion of their inward strokes.

- The ends of the cylinders and preferably the cylinder heads are provided with valves to permit regulation of the volume of air that is compressed within the cylinders and consequently vary the pressure produced by the pistons upon their inward strokes. The head of eachof the upper cylinders 27 is provided with a valve 40 that is, preferably, a one-way inlet valve, to permit substantially a free iiow of air into the cylinders 27 upon the downward or outward stroke of the piston 25.

The valve 40 is spring pressed by means of a suitable spring 41 which operates to return the valve to its seat to close the valve when the atmospheric pressure is the'same as that of the pressure within the cylinder. Upon the return stroke, the airthat is located in the cylinder rises to a pressure depending on the length of the inner stroke and depending upon the adjusted location ofthe telescoping parts of the cylinder. f

When, therefore, the cylinder 27 is filled with air the valve 40 is closed immediately in advance ofthe return stroke of the piston 25 and no more air enters the cylinder 27 except that that may enter to replace that which may leak out by reason of the rimperfections of the valve structure which, however, necessarily would be very small in amount even over a long period of operation of the machine. This produces a compression of the air within the cylinder 27 when the hammer @is lifted which stores energypotentially that is immediately converted into kinetic energy upon releasement or the hammer upon the opening movements of the rollers.

The lower cylinder 28, in each case, is provided with a valve 44. Preferably the valve 44 is controlled to regulate the movement of the air compressed by the piston. Preferably, the cylinder 28 is extended to provide a storage chamber to receive the air compressed bythe piston 28 and maintain the air at a temperature that will not affect the pressure normally produced by the piston and consequently maintain the lower cylinders at atmospheric temperature and eliminate drawing air .into the lower cylinders from the atmosphere and thereby eliminating drawing dust and particles into the cylinders that would eventually produce abrasion and cutting of the cylinders. This reduces wear and injury to the surfaces' over which the pistons move and consequently extends the life of the machine. economy of space and to locate the extensions of the cylinders 28 withinl the confines of the frame ofthe machine, each' head 30 is provided with an extension 46 that extends at right angles to the telescoping part 30 of the cylinder 28vand is locatedin the base 47 of the frame of the machine. The volume `of the chamber 46 may be varied but, preferably, itis about one-half of that of the cylinder 28 to produce a workable'return pressure within the extension 46 by the inward stroke of thepistons 26 in advance of the closingof the valves 44 and which will, however, be suiliciently large to prevent material cushioning of the stroke in advance of the impact produced by the hammer.

The valves 44 are automatically closed by any suitable mechanism at theV desired time to limit the blow and separate the head from the material by va quick return movement which is particularly advantageous where the hammer is working on plastic material, such as hot metal, and where there is apt to be any adherence to the hammer by reason of atmospheric pressure or by reason of the characteristic of the material that` is being worked upon. Y Thus, when the valve 44 .1

is closed the rate of increase of pressure is increased to a much higher rate to produce discontinuance of the downward movement of the hammer in a very short part of the movement of the hammer whereby the downward stroke of the hammer maybe controlled with an accuracy that enables eiicient manipulation of the hammer. 'I'his is particularly advantageous in the forming of articles. Y

In the particular form of construction shown, the frame 1 is provided with a shaft 48 on which is pivotally supported an arm 49 that is connected to a link 45. The link is also connected to a reciprocating part of the machine, such as the hammer head 5. Movement of the hammer head 5 causes the arm 49 to oscillate. The arm 49 is provided with a hub 50 and a collar 52. The hub is rotatable relative to the shaft 48 and the collar is keyed to the shaft. They are provided with the fingers 51 and 53. l The hub 50 and the collar 52 are connected together by means of a spring 54. A slidable cam member 55, preferably wedge shaped, is slidably movable between the ends of the ngers 51 and 53 to locate the iingers on the shaft 48 at a greater or less angle to each other. The cam 55, when pushed inward, operates to open or spread the fingers and advance the movement of the shaft y48 which is connected to the collar 52. The spring 54 operates to draw the ngers together, that is to produce a lesser angle For lower cylinders.

cylinders cooperates with the motor to initiateY between the ngeisand hold the ngers against the cam.

' The cam 55 is supported on a groov'ed wheel -56 that is rotatably supported. on the shaft 48 to enable short circular movements of the same. A bell `crank lever 57, suitably ksupported by means of the bracket 58 on the framev 1, is connectedby means of a suitable slip ring to the grooved wheel 56, one arm-of the crank lever 57r being provided with a suitable yoke whereby the shaft 48 may -be readily adjusted with reference to the movement of the arm 49 and, consequently, to thevmovement of the hammer head 5; Any suitable manual means vmay be provided Ifor operating the bell crank lever 57. In the formV of construction shownfthe pedal lever 64 is connected by means of a rod 59 to one of the arms of the bell crank lever 57 to vary the relation of the shaft 48 to the hammer head 5. A'suitable arm, such as the arm 60, is. connected 'to-arms 63 that operate the valves 44. Inthe form of construction shown, the valves 44 are rotary valves and are opened and closedk by 'angular movement ofthe valves. The arms 63 are connected'to the valves 44 to rotate them to open' and close the connections between the cylinders 28v and the extensions 46, to produce the desiredY compression of air within the extensions46 and, automatically, the quick riseV of pressure within the cylinders 28 at desired points in the opera-` tion of the hammer which is adjustably determined bythe position of the cam relative to the ngers 51 and 53. Y f

Thus, by my inventionf YI have provided a means for oscillatably supporting the hammer in what might be termed a normal-position and which lwill cause, upon displacement of the hammer, a-return pressure to return it to the normal that is quite in proportion to the displacement of the hammer from the normal. This provides a construction whereby the velocity of the down.- ward stroke is greatly increased and the momentum of the mass produces the impact. The force of the impact may be varied by the valves in the The compressed air in the lower thevupper movement and thus momentarily increases its momentum over that normally produced bythe motor and prevents wear on the upper end of the board. l The wear of the board is thus distributed uniformly over'the surface of the board Vwhich greatly increases the life of the machine. Theupward movement of the hammer and the pistons operate to compress the air in the upper cylinders and whenv the hammer is notwithstanding the compression of the air inthe extensions of thelower cylinders. If, however, the blow is regulated by closingthe valves 44 at the desiredpoint in the stroke of the hammer, the compressed air immediately cushions the hammer and initiates a high momentum in the hammer upwardly that is maintained by the motor operating through the rollers..

. In the form of structure illustrated in Figs. '7 and 8, the hammer head is controlled by the pressure' of air" produced in the lower` cylinders in the downward movement of the hammer. The air ressure' created by the lower piston automatic'ally operates `to close" the valves at the lower end of the cylinders in which the pistons move` to regulate the'extent of the movement of the' yand the shells 71.

hammer head, cushion its downward movement,

and elastically initiate its return movement. The

pressure created `by the lo-werpistons at which Y the hammer head will be cushioned in its down-v ward stroke may be manually varied at will and thus the hammer head isl subjected not only to an automatic pneumatic'control, but also 'to a manual'control.

As shown in Figs: 7 ands, the pistons 26'oper'-A ate in the lower cylinders and are connected to the piston rods 31 that are in turn vconnected to the hammer head, as in the form of construction shown in Figs. 4 and 5; The cylinders 70 Vare connected rto the shells 71 through suitable heads 72. The cylinders 70 may be threaded onto the heads 72 and the shells 7l maybe threadedV onto the heads 72, the shells 71 'forming eXtensions of thev chambersiwithin the cylinders 70. The chambers 71` have al volume that'is suitable for the creation of the desired lov/.pressure vto allow for movement of the air produced by the downward movement of the pistons and to allow 'for substantially free downward movement of the hammer head. Their relative volumes. are substantially the same as the relative volumes of the cylinders 28 and their extensions 46.

The shells 71 are provided with pneumatically i rod 77 may extend through the piston 78 and the outer end of the rod may be provided with a spring 80. A bell crank lever 84 has a slotted yoke 85A at kthe end of one of its arms and is adapted to operate a slidable plate 86 located on the outer end of the rod 77. The spring 80 is located intermediate the piston 78 and the plate 86. The bell crank lever 84 is pivotally mounted on the frame 1 o themachine and may be operated bya pedal lever 88 to which the bell crank lever 84 may be connected by means oi the link 89. Any suitable arrangement may be provided for manually operating the `bell crank levers to vary the pressure of the springs 80. Y

When thev hammer head descends the pistons 26 causeportions of the air to pass from the cylin ders 70 into the shells 71 through the walls 76 whenv thek valves 74 are opened Vand cause rise of pressure within the lowerY ends of the cylinders 70 This raises the pressure on the pistons 78 and enables them toovercome the pressur'eof the" springs 8G as determined by thek location of the bell crank levers 84 and the pedal lever 88; When the `pressure transmitted through the spring 80 is overcome by the piston 78ithe discs close the chambers in the shells 7 land the air ceases to escape from the lower end kof the cylinders 70 in the same manner as described in connection' with the closingV operation 'of thel valves 44. The hammer head ceases inits'down- Vward movement by Vthe rapid rise in pressure pro-` duced by the lower ends of the cylinders 70 and elastically cause a return movement and initiates a momentum that enables the motor to immediately continue to raise the hammer head. The h On the return movement of the pistons, the valves open when the pressure in the cylinders approach that of the pressure in the chambers of the shells and the pressure within the connecting chambers of the cylinders and the cylinders continue to cooperate with the motor to raise the hammer head.

I claim:

1. In a power driven machine, a vertical movable reciprocable weighted member, a pair of pistons and cylinders connected to the member to produce compression of air and a rise of pressure in proportion to the extent of the reciprocatory movement of the member, the pressure within one-of the cylinders decreasing and the pressure in the other of the cylinders increasing when the member moves in one direction and the said rising and decreasing pressures reversingl when the member moves in the opposite direction, a pair'of valves connected to the cylinders, the valve of the upper cylinder operable tov admit air at substantially atmospheric pressures into the cylinder and prevent air escape from the cylinder, a closed shell communicating with the lower cylinder, the valve of thelower'cylinder operable to open and close the communication between the lower cylinder and the shell, and means for operating the Valve of the lower cylinder Vto open and close the valve at they desired points in the movement of the member.

for maintaining atmospheric pressure upon completion of the outward expansion strokes relative to the cylinder parts and prevent .the escape of airtherefrom upon the return strokes,vv a chambered part having a passageway for connecting the chambered part to the other ofthe cylinder parts and having means for preventing movement of` air thereto and therefrom except throughv said passageway, a valve member located in the passageway for controlling the flow of air through the passageway, and means operated by the air pressure produced by the movement of the plunger for closing and opening the passageway by the valve whereby the plunger may be resiliently,- stopped when the air pressure of the lower cylinder part reaches a desired amount by marked reduction of the volume in which the air is compressed as the plunger moves downward,` and whereby the resiliency of` the air Vcauses vthe plunger to rebound and cooperate with the said` mechanical means.

3. In a power hammer, a weighted plunger, a mechanical means for raising the plunger, means for releasing the plunger from the rst named means for `free falling of the plunger relative to said first named means, pistonY and cylinder parts means operated by the plunger and connected to one of the piston and cylinder parts for producing decreasing pressure in one` cylinder part and at the same time increased pressure in the other cylinder part, means connected to the irst named cylinder part for maintaining atmospheric pressurel upon completion of the outward expansion strokes in the cylinder parts, achambered part having a passageway for connecting the chambered part to one of the cylinder parts, the said cylinder and chambered parts having means for preventing the escape of air from the cylinder parts and the chambered part, a valve member located in the passageway for controlling the ilow of air through the passageway, and a means operated by the movement of the plunger for operating the valve to close and open the passageway whereby the plunger may be resiliently stopped when the air pressure of the lower cylinder part reaches a desired amount by marked reduction of the volume in which the air is compressed as the plunger moves downward, and wherein the resiliency of the air causes the plunger to rebound and cooperate with the said mechanical means.

- 4. In a power hammer, a weighted plunger, a* mechanical means for raising Vthe plunger, means forreleasing the plunger from the rst named `means for free falling of the plunger relative to said first named means, piston and cylinder parts means operated by the plunger and connected to one of the pistons and cylinder parts "for producingV decreasing pressure in one cylinder part and at the same time increased pressure inthe other cylinder part, means connected to the first named cylinder part for maintaining atmospheric pressure upon completion of the outward expansion strokes in the cylinder parts, a chambered part having a passageway for connecting the chambered partto one of the cylinder parts, the said 'cylinder and chambered parts having means for preventing the escape of air from the cylinder parts and the chambered part, a valve member located in the passageway for controlling the flow of air through the passageway, and means'operated by the air pressure produced by the movement of theplunger for operating the valve to close and open the passageway and manually operated means for varying the last named means to vary the points of closing the valve in the movement of the plunger whereby the plunger will be normally resiliently stopped in its downward movement at predetermined points that may be manually varied to control the completion of the downward blow as material is hammered and pneumatically cause rebound 'of the plunger after each blow'in cooperation with the said mechanical means.

5. In a powerhammer, a weighted plunger, a mechanical means for raising the plunger, means for releasing the plunger from the first named means for free falling of the plunger relative to said first named means, piston and cylinder parts means operated by the plunger and connected to one of the piston and cylinder parts for producing decreasing Apressure in one cylinder part and at the same` time increased pressure in the other cylinder part, means connected to the rst named cylinder part for maintaining atmospheric pressure upon completion of the outward expansion strokes in the cylinder parts, a chambered part having va passageway -for connecting the chambered part to one of the cylinder parts, the said cylinder and chambered parts having means for preventing the Vescape of air from the cylinder parts and the chambered part, a valve member located in the passageway for controlling the flow of air through the passageway, means operated by vthe airpressure produced by the movement of the plunger for operating the valve to close and open the passageway by the valve, and means for manually operating the valve for varying the Valve closing in the movement of the plunger by the valve member whereby theplunger may be resiliently stopped when the air pressure of the lower cylinder part reaches a desired amount by marked reduction of the volume in which the air is compressed as the plunger moves downward, and wherein the resiliency of the air causes the plunger to rebound and cooperate with the said mechanical means.

` 6. In a power hammer, a weighted plunger, a mechanical means for raising the plunger, means for releasing the plunger from the first named means, a piston member and cylinder parts, the piston member movable within the cylinder parts and connected to the plunger, one of the cylinder parts completely closed except for an air inletl one-way valve, the other of the cylinder parts having a chambered part, the chambered part having a passageway communicating with one end of the last named cylinder part, thel said end of the last named cylinder part and the chambered part completely closed except for the said passageway, a valve member located in the passageway for controlling the flow of air through the passageway, manually controlled means actuated by the movement of the plunger for operating the valve member whereby the plunger may be resiliently stopped when the air pressure of the lower cylinder part reaches a desired amount by marked reduction of the volume in which the air is compressed as the plunger moves downward, and wherein the resiliency of the air causes chambered part having a passageway communieating with one end of the last named cylinder part, the said end of the last named cylinder part'and the chambered part completely closed except for the said passageway, a valve member located in the passageway for controlling the iiow of air through the passageway, and means operatedby the pressure of air produced by the movement of the plunger for operating' the -valve to close and open the passageway whereby the plunger may be resiliently stopped when the air pressure of the lower cylinder part reaches a desired amount by marked reduction of the volumev in which the air is compressed as the plunger moves downward, and wherein the resiliency of the air causes the plunger to rebound and cooperate with the said mechanical means.

BERTIs H URSCHEL- 

